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Ground pearls (Hemiptera: Margarodidae), so called for their shiny spherical cyst stage, are important root-feeding pests of a broad range of plants predominantly belonging to the family Poaceae. In the tropical and subtropical regions of eastern Australia, ground pearl species cause significant damage on sugarcane and turf grasses and have been identified at multiple sites of pasture dieback in Queensland. The potential impact of ground pearls on pasture production in Australia and elsewhere is largely unknown. This paper reviews Australian and international literature on the biology and management of this poorly understood group of pests. Ground pearls have several features that make control difficult, including a resilient cyst which provides resistance to drought and excessive moisture, a relative impermeability to insecticides, and ease of dispersal through movement of soil. Ground pearls can also modulate the period of encystment to survive adverse environmental conditions, with some species capable of surviving for years while disassociated from a host. No insecticide effectively controls ground pearl cysts. Biological control agents have been identified for some species; however, these pathogens are relatively ineffective on subterranean ground pearl cysts. Cultural control methods such as cultivation and fallowing have helped to reduce ground pearl populations in sugarcane. In turf, practices that maintain plant health such as adequate irrigation and nutrition can mask signs of ground pearl infestation. The paucity of research conducted on the biology and impact of ground pearls represents a constraint to improving management of this pest. Ground pearls are important pests of a broad range of plants predominantly belonging to the grass family (Poaceae). In eastern Australia, they cause significant damage on sugarcane and turf grasses, and have recently been found in pasture situations in Queensland, but their impacts are unknown. This work reviews Australian and international literature on the biology and management of ground pearls, finding that relatively little research has been undertaken and several knowledge gaps remain. [ABSTRACT FROM AUTHOR]

Many farmers in Australia and in other countries have a choice of crop or livestock production, and many choose a mixture of both, based on risk preference, personal interests, markets, land resources and local climate. Mixed farming can be a risk-spreading strategy, especially in highly variable climates, but the right scales of each enterprise within the mix may be critical to farm profitability. To investigate expected farm profits, the probability of breaking even, as well as the worst and best case scenarios, we used farm data and APSIM (Agricultural Production Systems Simulator) to simulate the production of a typical, semi-arid, mixed-farm in southern Queensland. Three farming system scenarios were investigated: I, livestock and more intensive cropping; II, current production system of livestock and minimal cropping; and III, livestock only. We found that the expected profits were in the order system I > system III > system II. The key reason for the lower profits of system II was the high overhead cost of capital to continue some cropping, with low annual cropping income. Under the worst case scenario, in years with low rainfall, system I had the greatest downside risk with far greater financial losses. Systems I and III had similar probabilities of breaking even, and higher than system II, which incurs cropping overheads and limited cropping returns. Therefore, system II was less desirable than either system I or III. This case study helps farmers and advisors of semi-arid mixed farming enterprises to be better informed when making decisions at the paddock and whole-farm level, in both the short and long term, with respect to profit and risk. The method used in this paper can be applied to other mixed farms, in Australia and elsewhere. [ABSTRACT FROM AUTHOR]

Context: Mungbean (Vigna radiata (L.) Wilczek) is an important grain legume for food, feed, and green manure. Mungbean yield is highly variable due to fluctuating temperature and unpredictable rainfall. Aims: To improve yield stability, it is critical to utilise a model that can simulate mungbean phenology, biomass, and yield accurately. Methods: A thorough understanding of the physiological determinants of growth and yield is required to advance existing mungbean crop modelling capability. Currently, there is limited understanding of the physiological determinants of canopy and reproductive development and their variation in mungbean germplasm. Two experiments (controlled and field environments) were conducted at Gatton, Queensland, in 2018–19. Six Australian mungbean genotypes and one black gram (Vigna mungo L.) were grown under non-limiting conditions. Plant phenotypic traits (canopy development, time to first, 50% flowering, duration of flowering and podding, flower appearance, pod addition rates) were recorded. Key results: Genotypes M10403 and Satin II had significantly higher leaf appearance rate (LAR). Genotypes with a greater LAR had higher number of leaves but lower individual leaf area. Genotypes varied significantly in time to first and 50% flowering, with Onyx-AU (black gram) and Celera II-AU flowering earliest. Flowering and podding rates, and duration of these phenological phases varied among genotypes. Total plant leaf area (TPLA) approached its maximum at mid-podding stage. Implications: This study quantified the key phenotypic and physiological relationships associated with canopy and reproductive development, critical for the improvement of mungbean crop modelling required to accurately simulate growth and development and inform possible canopy constraints that are limiting mungbean productivity. Yield variability in mungbean is a consequence of fluctuating temperature and unpredictable rainfall. Enhanced understanding and quantification of the determinants of canopy and reproductive development will support improving crop models and simulating strategies for improved crop adaptation. This study quantified differences among genotypes in reproductive development, leaf appearance rate, and leaf size. However, in all cases, total plant leaf area approached a maximum at mid-podding stage as a consequence of source-sink dynamics. [ABSTRACT FROM AUTHOR]